Vacuum arc furnace having centrifugal casting means

ABSTRACT

A vacuum arc furnace in combination with a centrifugal casting machine having a first melting chamber and a second chamber for pouring molten metal into moulds is disclosed. Mounted under the chambers is a centrifugal casting machine fitted with a detachable table including carrying moulds and including a drive for elevating the table in a vertical direction. The drive rotates the elevated table with the moulds thereon having molten metal.

United States Patent [191 Glazunov et al.

[111 3,807,488 [451 Apr. 30, 1974 VACUUM ARC FURNACE HAVING CENTRIFUGAL CASTING MEANS [76] Inventors: Sergei Georgievich Glazunov,

Leninsky prospekt, 41,.kv. 62, Moscow; Ilya Alex'androvich Zhikharev, shosse Entuziastov, 7, kv. 5, Balashikha Moskovskoi oblasti; Dmitry Alexandrovich Filippov, Saratovskaya ulitsa, 18/101, kv. 138, Moscow; Pavel Vladimirovich Norin, 9 ulitsa Sokolinoi Gory, l, kv. 6, Moscow; Viktor lvanovich Zasulsky, Leningradsky prospekt, 60-a, kv. 54, Moscow; Konstantin Konstantinovich Yasinsky, l Vladimirovskaya ulitsa, l0, kv. 32, Moscow; Alexei Mikhailovich Khromov, 9 ulitsa Sokolinoi Gory, 3, kv. 211, Moscow; Illarion Afanasievich Prostov, ulitsa Kuusiena, 6, korpus 13, kv. 1088,

Moscow; Anatoly Sergeevich Romanov, ulitsa Kakhovka, l3, korpus l, kv. 136, Moscow; Alexei Mikhailovich Ivanov, 9 ulitsa Sokolinoi Gory, 3, kv. 245, Moscow; Elena Arkadievna Kashina, Leninsky raion, stantsia Bulatnikovo, ulitsa Kolkhoznaya, 7, Moskovskaya oblast; Nina Sergeevna Gorina-Valeeva, Nikitinskaya ulitsa, 9, kv. 39, Moscow; Mikhail Pavlovich Kuleshov, Rzhev, Sovetskaya ploschad, ll, kv. 23; Pavel lvanovich Smirnov, Rzhev, Sovetskaya ploschad, l1, kv. 11, both of Kaliniskaya oblast; Vyacheslav Alexeevich Nikolaev, Leningradskoe shosse, 1 12/1 korpus l, kv. 21, Moscow; Igor Borisovich Krjuchkov', Begovaya ulitsa, 22, korpus l6, kv. 68, Moscow; Veniamin Vladimirovich Musatov, Beskudnikovo, proezd Cherskogo, l3, kv. 17, Moscow;

Valery Moiseevich Moldavsky, Sirenevybulvar, 41, kv. 35, Moscow; Leonid Alexandrovich Khrustsevich, ulitsa Kolesovoi, 5, kv. 3, Moscow; Vladimir Ilich Nekrasov, Novo-Gireevo, Bratskaya ulitsa, 27, korpus 3, kv. 79, Moscow; Galina Fedorovna Lyapina, Utrennaya ulitsa, 18, korpus l, kv. 17, Moscow; Nikolai Andreevich Fedoseev, Samokatnaya ulitsa, 3/8, kv. 123, Moscow, all of U.S.S.R.

221 Filed: Mar. 1,1972

21 Appl. No.: 230,626

Primary Exaniiner.l. Spencer Overholser Assistant Examiner-John E. Roethel Attorney, Agent, or Firm-Holman & Stern [5 7] ABSTRACT A vacuum arc furnace in combination with a centrifugal casting machine having a first melting chamber and a second chamber .for pouring molten metal into moulds is disclosed. Mounted under the chambers is a centrifugal casting machine fitted with a detachable table including carrying moulds and including a drive for elevating the table in a vertical direction. The drive rotates the elevated table with the moulds thereon having molten metal.

4 Claims, 2 Drawing Figures VACUUM ARC FURNACE HAVING CENTRIFUGAL CASTING MEANS BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to vacuum arc furnaces for melting chemically active metals followed by pouring them into mould ofa centrifugal casting machine to produce thin-walled workpieces.

DESCRIPTION OF PRIOR ART Known in the prior art is a vacuum arc furnace for melting chemically active metals to be fed subsequently into moulds of a centrifugal casting machine mounted on a bogie or a wagon. A melting chamber of the furnace is fitted with a melting crucible and a consumable electrode. The melting chamber is separated by a vacuum gate valve from a second chamber located beneath and designed for accommodating the centrifugal casting machine. This second chamber with the centrifugal casting machine is installed on the self-propelled wagon and is capable of travelling along a rail track in a horizontal direction.

As the centrifugal casting machine is mounted on a wagon and not on a rigid foundation, intense vibrations are liable to originate in operation which would damage the moulds and thus'badly affect the quality of workpieces. As part of the centrifugal casting machine, a table with the mo'ulds is rigidly fixed on a shaft of the centrifugal casting machine and is separated from a crucible at a considerable distance. Consequently in order to direct a metal stream as well as to reduce spattering and stream impact, use is made of additional facilities, such as spouts and pouring cups. At the same time an objectionable cooling of metal occurs which decreases its fluidity. As a result the production of high quality thin-walled castings in these furnaces is difficult and presents a problem.

SUMMARY OF THE INVENTION liquid metal and a chamber located beneath the vac-' uum chamber on a self-propelled wagon and intended for distributing the liquid metal among moulds set up on a table of a centrifugal 'castingmachine; conforming to this invention, the centrifugal casting machine is sta-. tionarily fixed and has a drive to shift in a vertical direction the detachable table which is enclosed in the chamber for distributing the liquid metal and is moved together with that chamber equipped with an upper and lower gate valves making'it airtight.

Such a furnace makes it possible to increase the productive time of the furnace by replacing rapidly the chamber for distributing the liquid metal among the moulds. In addition, a stationary and rigid location of the centrifugal casting machine makes it more stable and precludes the incidence of vibrations which tend to arise due to a non-rigid fastening.

It would be expedient to use in a centrifugal casting machine a hydraulic cylinder which acts as a drive to move the table and as a frame of the centrifugal casting machine and in which a rod is provided through which passes a spindle holding the table and imparting a rotary movement thereto from the drive.

This ensures the movement of the table which has mounted on moulds in a vertical direction; hence, a need for auxiliary equipment such as troughs is obviated and metal cooling and spattering are reduced.

In the chamber for distributing the liquid metal it is desirable to mount centering pins in order to hold in place the table disconnected from the spindle of the centrifugal casting machine and to move it subsequently in conjunction with the chamber.

The pins shall keep the table of the centrifugal casting machine from being displaced when it is rolled back and then returned together with the chamber for distributing the liquid metal. This will ensure a reliable connection between the spindle of the centrifugal ma chine and its table.-

It is expedient to locate the centrifugal casting machine below the level at which the chamber for distributing the liquid metal among the moulds is mounted.

BRIEF DESCRIPTION OF THE DRAWINGS To make the essence of this invention more clear, given below is a description of an exemplary embodiment to be considered with due reference to the accompanying drawings, wherein:

FIG. 1 is a fragmentary cut-away view of the side wall of a vacuum arc furnace; 7

FIG. 2 depicts the same vacuum arc furnace with detached chamber for distributing liquid metal and with theenclosed in it table.

A vacuum furnace for the centrifugal casting of metal workpieces has a vacuum chamber 1 (FIGS. 1 and 2) with consumable electrode 2 and crucible 3 for producing liquid metal and chamber 5 arranged below it on bogie 4 and intended for distributing the liquid metal among moulds 6 set up on table 7 of centrifugal casting machine 8.

As centrifugal casting machine 8 is disposed stationary, and fixed its vibrations are not transmitted to either chambers 1 and 5 of the vacuum arc furnace or moulds 6 mounted on table 7 of centrifugal machine 8. To move table 7 in a vertical direction drive 9 is provided, consisting of hydraulic cylinder 10 acting as a frame, and rod 11 representing a tailspindle through which spindle 12 passes which serves to hold table 7 and to impart it rotation from drive 13. Table 7 can be coupled with spindle 12 for rotation therewith by means of a projection and a recess which can be provided on the parts to be coupled togetherfor rotation.

Chamber for distributing the liquid metal among moulds 6 set up on a table 7 is equipped with vacuum gate valves 14, 15 making itair-tight, and pins 16 centring table 7 and keeping it after it has been detached from the spindle of centrifugal casting machine 8.

For sealing chamber 1 vacuum gate valve 17 is mounted at its bottom.

Under chamber for distributing the liquid metal there is a base plate 18 the purpose of which is to force said chamber 5 against the butt end of chamber 1 and to provide with the aid of packing l9 sufficient and dependable air-tightness of the furnace, as a whole, in the course of operation.

Base-plate 18 is fitted with a hole to receive spindle 12 of centrifugal machine 8 to be coupled subsequently with table 7 carrying moulds 6. Inserted in the hole of base-plate 18 is an air-tight cup (not shown in the drawing).

pipe 20 provided in vacuum chamber 1 and connecting pipe 21 in base-plate 18.

The vacuum arc furnace functions as follows.

A consumable electrode 2 having an adequate weight for carrying out several heats is inserted in vacuum chamber 1. Under vacuum chamber 1 is set up the chamber 5 having the table 7 carrying thereon moulds 6 intended to receive the metal being poured and to produce workpieces. Chambers 1 and 5 are set in communication with each other by means of the vacuum gate valves and the base-plate 18 is forced against them, whereupon the air from the entire volume of the furnace is evacuated via connecting pipes 20 and 21 coupled to a vacuum system (not shown in the drawing). The drive 9-is turned on next and the rod 11 is moved up from hydraulic cylinder together with spindle 12 in the direction of detachable table 7. The locking device with the projection provided in the upper portion of spindle 12 (not shown in the drawing) is inserted into and engaging an opening in the lower portion of table 7, with both parts being therefore joined together, and drive 9 raises table 7 with moulds 6 to a specified height.

Then consumable electrode 2 is melted in crucible 3 which is located and enclosed in vacuum chamber 1'. At the same time drive 13 of centrifugal casting machine 8 is cut in, the drive being intended to rotate table 7.

After the requisite amount of liquid metal is produced in crucible 3, the metal is poured into moulds 6 mounted on table 7 of centrifugal casting machine 8.

As soon as the moulds are filled up with the metal, gate valve 17 is closed to separate vacuum chamber 1 from chamber 5 which is also closed by upper vacuum gate valve 14.

Both the electrode 2 and the crucible 3 are hot at this time. Detachable table 7 stops rotating and lowers on centering pins 16, made in the form of anchor plates. As rod 11 of hydraulic cylinder 10, which is the tail spindle of centrifugal casting machine 8, is coming down, it is detached from table 7 and lowered so that it is drawn into the interior of hydraulic cylinder 10 and is not in the way of lower gate valve closing chamber 5 from below.

Chamber 5 is disconnected from the furnace and rolled away, and replaced with another chamber accommodating a similar table 7 with moulds 6 ready to accept molten metal for casting.

The cycle is repeated until all the electrode 2 is consumed. The furnace gears are controlled from a central control panel.

What is claimed is:

l. A vacuum arc furnace for the centrifugal casting of metal workpieces comprising: a vacuum chamber having a consumable electrode and a crucible disposed therein for producing molten metal from the consumable electrode; a second chamber provided for distributing the molten metal among moulds, said second chamber being mounted under the said first vacuum chamber on a mobile carriage; a centrifugal casting machine having a detachable rotary table carrying moulds thereon and stationarily fixed under'the said second chamber so that only said detachable table carrying the moulds projects into and is enclosed in said second chamber; a drive of the said centrifugal casting machine having means for displacing said table in a vertical direction and towards the bottom of said vacuum chamber to facilitate tapping of molten metal from said crucible into said moulds, said drive of the centrifugal casting machine also having means to rotate the detachable table with the moulds so as to cause centrifugal forces on molten metal in the moulds; and gate valves making the said second chamber for distributing the molten metal air-tight.

2. A vacuum arc furnace as of claim 1 in which said means for vertically displacing the table comprises a hydraulic cylinder acting as a drive for moving said table, said cylinder acting as a frame and having an associated piston rod, and a tail spindle through which is passed a spindle holding the table and imparting a rotary movement to the table from the drive.

3. A vacuum arc furnace as of claim 1 in which said centrifugal casting machine is located at a lower level relative to the said second chamber for distributing the liquid metal among the moulds.

4. A vacuum arc furnace for the centrifugal casting of metal work pieces, comprising:

a vacuum chamber having a consumable electrode anda crucible disposed therein for producing molten metal from the consumable electrode;

a second chamber provided for distributing the molten metal among moulds, said second chamber being mounted under said first vacuum chamber on a mobile carriage;

a centrifugal casting machine having a detachable rotary table carrying moulds thereon and stationarily fixed under said second chamber so that only said detachable table carrying the moulds projects into and is enclosed in said second chamber;

a drive of said centrifugal casting machine having means for displacing said table in a vertical direction and towards the bottom of said vacuum chamber to facilitate tapping of the molten metal from said crucible into said moulds, said drive of said centrifugal casting machine also having means to rotate the detachable table with the moulds so as to cause centrifugal forces on molten metal in the moulds;

said second chamber for pouring molten metal into the moulds having centering retainers arranged to keep said detachable table disengaged from the spindle of said centrifugal machine and subsequently displacement thereof together with said second chamber; and

gate valves making said second chamber fordistributing the molten metal air-tight. 

1. A vacuum arc furnace for the centrifugal casting of metal workpieces comprising: a vacuum chamber having a consumable electrode and a crucible disposed therein for producing molten metal from the consumable electrode; a second chamber provided for distributing the molten metal among moulds, said second chamber being mounted under the said first vacuum chamber on a mobile carriage; a centrifugal casting machine having a detachable rotary table carrying moulds thereon and stationarily fixed under the said second chamber so that only said detachable table carrying the moulds projects into and is enclosed in said second chamber; a drive of the said centrifugal casting machine having means for displacing said table in a vertical direction and towards the bottom of said vacuum chamber to facilitate tapping of molten metal from said crucible into said moulds, said drive of the centrifugal casting machine also having means to rotate the detachable table with the moulds so as to cause centrifugal forces on molten metal in the moulds; and gate valves making the said second chamber for distributing the molten metal air-tight.
 2. A vacuum arc furnace as of claim 1 in which said means for vertically displacing the table comprises a hydraulic cylinder acting as a drive for moving said table, said cylinder acting as a frame and having an associated piston rod, and a tail spindle through which is passed a spindle holding the table and imparting a rotary movement to the table from the drive.
 3. A vacuum arc furnace as of claim 1 in which said centrifugal casting machine is located at a lower level relative to the said second chamber for distributing the liquid metal among the moulds.
 4. A vacuum arc furnace for the centrifugal casting of metal work pieces, comprising: a vacuum chamber having a consumable electrode and a crucible disposed therein for producing molten metal from the consumable electrode; a second chamber provided for distributing the molten metal among moulds, said second chamber being mounted under said first vacuum chamber on a mobile carriage; a centrifugal casting machine having a detachable rotary table carrying moulds thereon and stationarily fixed under said second chamber so that only said detachable table carrying the moulds projects into and is enclosed in said second chamber; a drive of said centrifugal casting machine having means for displacing said table in a vertical direction and towards the bottom of said vacuum chamber to facilitate tapping of the molten metal from said crucible into said moulds, said drive of said centrifugal casting machine also having means to rotate the detachable table with the moulds so as to cause centrifugal forces on molten metal in the moulds; said second chamber for pouring molten metal into the moulds having centering retainers arranged to keep said detachable table disengaged from the spindle of said centrifugal machine and subsequently displacement thereof together with said second chamber; and gate valves making said second chamber for distributing the molten metal air-tight. 